PLATE XLI. 
Pecren (continued). 
Figs. 
1—8. P. (Neithea) sexcostatus, Woodw. 1—5, Form B, Upper Chalk. 6—8, 
Form a, Lower Chalk. (P. 214.) 
1. A. quadratus zone, East Harnham, Salisbury. Dr. Blackmore’s Collection. 
a, right valve; b, portion of the two middle main ribs and part between x 4. 
2. Same horizon, etc. a, right valve; b, posterior view of the same. 
3. B. mucronata zone, Hartford Bridge, Norwich. Woodwardian Museum. 
a, right valve x 13; b, portion of the same near the ventral margin x 4; 
c, portion dorsal to middle of valve x 4. 
nN 
. B. mucronata zone, Norwich. Norwich Museum. Right valve x 2. 
Oo 
. A. quadratus zone, East Harnham. Dr. Blackmore’s Collection. Right valve. 
Portion of the two middle main ribs and part between x 4. 
6—8. Chalk Marl, Dover. Woodwardian Museum. Right valves. 6a, x 13; 6), 
posterior view of the same x 2; 6c, part between two main ribs x 4 7a, 
x 13; 76, posterior view of the same x 1}; 7c, part between two main ribs 
x 4. 8a, x 15; 8b, part between two main ribs x 4. 
9,10. P. (Neithea) striatocostatus 2? Goldf. Chalk, Trimingham. Museum of 
Practical Geology (Coll. Mr. Clement Reid). (P. 217.) 
9a, portion of right valve; 9b, part of the same x 6. 10a, left valve x 2; 
106, part of the same x 5. 
Genus—V ELoPECctEn, Philipp. 
ll. V. Studeri (Pict. and Roux). Upper Greensand, Warminster. York 
Museum. (P. 218.) 
lla, left valve; 116, part of the same x 2; I1c, right valve of the same specimen. 
